codec: add ability to pass codec options

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

codec/codec.go

@@ -41,11 +41,11 @@ type MessageType int
 // connection. ReadBody may be called with a nil argument to force the
 // body to be read and discarded.
 type Codec interface {
-	ReadHeader(io.Reader, *Message, MessageType) error
-	ReadBody(io.Reader, interface{}) error
-	Write(io.Writer, *Message, interface{}) error
-	Marshal(interface{}) ([]byte, error)
-	Unmarshal([]byte, interface{}) error
+	ReadHeader(r io.Reader, m *Message, mt MessageType) error
+	ReadBody(r io.Reader, v interface{}) error
+	Write(w io.Writer, m *Message, v interface{}) error
+	Marshal(v interface{}, opts ...Option) ([]byte, error)
+	Unmarshal(b []byte, v interface{}, opts ...Option) error
 	String() string
 }
 

codec/noop.go

@@ -5,7 +5,9 @@ import (
 	"io"
 )
 
-type noopCodec struct{}
+type noopCodec struct {
+	opts Options
+}
 
 func (c *noopCodec) ReadHeader(conn io.Reader, m *Message, t MessageType) error {
 	return nil
@@ -69,11 +71,11 @@ func (c *noopCodec) String() string {
 }
 
 // NewCodec returns new noop codec
-func NewCodec() Codec {
-	return &noopCodec{}
+func NewCodec(opts ...Option) Codec {
+	return &noopCodec{opts: NewOptions(opts...)}
 }
 
-func (c *noopCodec) Marshal(v interface{}) ([]byte, error) {
+func (c *noopCodec) Marshal(v interface{}, opts ...Option) ([]byte, error) {
 	if v == nil {
 		return nil, nil
 	}
@@ -96,7 +98,7 @@ func (c *noopCodec) Marshal(v interface{}) ([]byte, error) {
 	return json.Marshal(v)
 }
 
-func (c *noopCodec) Unmarshal(d []byte, v interface{}) error {
+func (c *noopCodec) Unmarshal(d []byte, v interface{}, opts ...Option) error {
 	if v == nil {
 		return nil
 	}

codec/options.go

@@ -1,6 +1,8 @@
 package codec
 
 import (
+	"context"
+
 	"github.com/unistack-org/micro/v3/logger"
 	"github.com/unistack-org/micro/v3/meter"
 	"github.com/unistack-org/micro/v3/tracer"
@@ -19,6 +21,10 @@ type Options struct {
 	Tracer tracer.Tracer
 	// MaxMsgSize specifies max messages size that reads by codec
 	MaxMsgSize int
+	// TagName specifies tag name in struct to control codec
+	TagName string
+	// Context stores additional codec options
+	Context context.Context
 }
 
 // MaxMsgSize sets the max message size
@@ -28,6 +34,13 @@ func MaxMsgSize(n int) Option {
 	}
 }
 
+// TagName sets the codec tag name in struct
+func TagName(n string) Option {
+	return func(o *Options) {
+		o.TagName = n
+	}
+}
+
 // Logger sets the logger
 func Logger(l logger.Logger) Option {
 	return func(o *Options) {
@@ -52,10 +65,12 @@ func Meter(m meter.Meter) Option {
 // NewOptions returns new options
 func NewOptions(opts ...Option) Options {
 	options := Options{
+		Context:    context.Background(),
 		Logger:     logger.DefaultLogger,
 		Meter:      meter.DefaultMeter,
 		Tracer:     tracer.DefaultTracer,
 		MaxMsgSize: DefaultMaxMsgSize,
+		TagName:    DefaultTagName,
 	}
 
 	for _, o := range opts {